Coins a pain in the butt to deal with, being dirty, easily misplaced, make your wallet go all funny, and pretty heavy in aggregate. So what if you could make a cash purchase at the drug store, and instead of getting $.82 in change, you get a QR code on your receipt that your phone can scan and put that 82 cents towards your next purchase at Amazon, iTunes, Moneypak, Paypal, Mt. Gox, etc? Not quite a Bitcoin product since it would be on a long list of affiliates, but I thought it would be a decent idea to kick around, and I figured I go here first cause I'd rather have you guys snatch it out from under me than Coinstar.

So say you're supposed to get 2.25 in change from Walmart, if you opt to get a QR-code instead but it could only be used with certain online merchants, and you would get a 10% bonus or something like that for using it, it might work.

Coins a pain in the butt to deal with, being dirty, easily misplaced, make your wallet go all funny, and pretty heavy in aggregate. So what if you could make a cash purchase at the drug store, and instead of getting $.82 in change, you get a QR code on your receipt that your phone can scan and put that 82 cents towards your next purchase at Amazon, iTunes, Moneypak, Paypal, Mt. Gox, etc? Not quite a Bitcoin product since it would be on a long list of affiliates, but I thought it would be a decent idea to kick around, and I figured I go here first cause I'd rather have you guys snatch it out from under me than Coinstar.

That's actually a pretty decent idea. Or a variation -- instead of paying out coins for your change, that amount just gets an electronic debit into an account that acts like (or is linked to) a prepaid debit card. Since it is going from the merchant to the customer, there's no pin # or anything else needed from the customer -- just their magstripe card or QR code, or even just a phone number. I wouldn't be surprised if something like this already exists.

Merchants would love it because it can now tie customers that pay cash even to its customer database / analytics / data mining systems. And that's were my interest in seeing this succeed ends.

That's actually a pretty decent idea. Or a variation -- instead of paying out coins for your change, that amount just gets an electronic debit into an account that acts like (or is linked to) a prepaid debit card. Since it is going from the merchant to the customer, there's no pin # or anything else needed from the customer -- just their magstripe card or QR code, or even just a phone number. I wouldn't be surprised if something like this already exists.

Merchants would love it because it can now tie s customers that pay cash even to its customer database / analytics / data mining systems. And that's were my interest in seeing this succeed ends.

So, as opposed to paying for something with a piece of plastic attached to a bank account, you're going to pay in paper money, and get your return on a piece of plastic that's attached to your bank account?

The average person on the street would normally just want their change in physical coins unless, of course, the average user is a gamer, then between them and their parents they'll be able to amass x amount of bitcoins during the course of a week, using their coins to purchase wares for their games. The merchant now has an added incentive in providing this service, for he'll get a kickback from the game developers. In fact, he'll be able to double-dip if he procures bitcoins at a rate lower than what he has to dole out. Now, if the proprietor manages the store of which is owned by him and other investors, and those investors split the operating cost, his electric expense for mining would be lower than the average miner. Taking this idea one step further, if the owner of this fictitious 7-11 sold his surplus bitcoins to family members back in India at a rate higher than prevailing, then he's golden.

If I understand correctly the idea, the store's checkout system 1/ generates a key pair 2/ prints out the QR code of the privkey on the cash receipt and 3/sends out the change to the bitcoin address.This is a killer app: saves a LOT of time for the merchant and reduces waiting time for customers paying in cash.The customer can easily redeem the privkey on strongcoin.com or equivalent at a later time when its convenient for her.Most importantly, this will attract many new users to bitcoin.Metal coin usage could be reduced dramatically.

If I understand correctly the idea, the store's checkout system 1/ generates a key pair 2/ prints out the QR code of the privkey on the cash receipt and 3/sends out the change to the bitcoin address.

One slight problem some might have with that though is that the customer cannot redeem the code instantly -- as the transaction by the merchant to load the funds to the address on the QR code from the receipt doesn't confirm immediately. The key from the QR code could be imported immediately, just that it couldn't be redeemed / swept immediately. This probably isn't a major problem but it detracts from the benefits of the concept slightly.

The customer can easily redeem the privkey on strongcoin.com or equivalent at a later time when its convenient for her.

A problem might will occur where there is difficulty in redeeming the code. When the redemption doesn't occur immediately (e.g., while still in the store) then some of that "difficulty" will be the result of attempted fraud (e.g., claimed the code then makes a complaint that the code couldn't be redeemed.) and some will be for other reasons (customer couldn't figure it out, technical problems, etc.).

The risk of fraud will probably kill this idea before it even gets off the launch pad though. The employer cannot prove the customer is in the wrong, so the end result is either the merchant ends up denying refunds to innocent customers who were truly unable to obtain their change (e.g., when the merchant itself runs an insecure system) or the merchant gives refunds for most claims and as a result the amount of fraudulent claims (and thus the cost of offering this) skyrockets.

So maybe requiring the customer to provide the public bitcoin address (obtained with a card swipe perhaps) is the only workable method for this. There's no liability on the merchant's end -- the receipt provided shows the bitcoin address that was scanned and includes as well transaction info for the change payment that can be verified against the block chain.

So maybe requiring the customer to provide the public bitcoin address (obtained with a card swipe perhaps) is the only workable method for this. There's no liability on the merchant's end -- the receipt provided shows the bitcoin address that was scanned and includes as well transaction info for the change payment that can be verified against the block chain.

What you are suggesting is most certainly an improvement over the "key pair generation" I described above: key pair generation by the store cash system would be a fallback solution for customers interested in trying the system but not yet carrying a swipe card.Some customers will prefer not to carry another card and delay redemption until they are back home or until they have collected a bunch of receipts (they would not care so much about immediate redemption).Since this is obviously an opt-in system, the merchant can adjust his obligations accordingly.